Although axonal transport of some macromolecules as well as cell organelles has been demonstrated, the evidence supporting the transport of RNA in nerve axons is in some doubt. We have studied axonal RNA, labeled by injecting H3-uridine into goldfish eyes, and have proposed that in this system RNA is synthesized in the retina and then transported along regenerating optic axons to the reinnervated tectum. Experiments are planned to study this phenomenon further in regenerating nerves, and also to try to offer conclusive evidence as to whether RNA is transported in normal nerves as well. These experiments are proceeding along several different experimental lines: (1) A graduate student and I plan to study RNA transport in normal and regenerating sciatic nerves of rats in an attempt to correlate our findings in regenerating optic nerves of goldfish with regenerating peripheral nerves of mammals; (2) studies on the gel electrophoretic characterization of transported RNA in normal and regenerating nerves in both goldfish optic and rat sciatic nerves will be continued; (3) the electron microscopic autoradiographic localization of transported RNA in these nerve fibers will be determined by quantitative experimental techniques. These experiments are presently under way and attempts will be made to more precisely localize axonal RNA by utilizing methods of involving a physical developer to develop silver grains associated with RNA; (4) finally, since experiments indicate a very close association between nucleic acids and polyamines, we plan to study the transport of radioactive polyamines in normal and regenerating nerve fibers.